Amorphous indium–gallium–zinc-oxide (a-IGZO) is an n-type semiconductor widely used in transparent electronic devices [1,2,3]. Due to its suitable properties like ~3 eV band gap, high charge mobility and good chemical stability this material is considered to be the lower-cost alternative for LTPS (low-temperature polysilicon) in high-pixel-density displays.  The IGZO-based transistors are slightly photo-sensitive in visible domain. Their photo-sensitivity is boosted in ultra-violet (photon energy above 3 eV) range. This propriety is explored in this work in order to emphasize the photoconductivity of the IGZO semiconductor.  IGZO thin films were fabricated by radio-frequency magnetron sputtering under various deposition regimes. The sputtered IGZO thin films were integrated in micro-sized thin film field effect transistors (TFTs) with 50 nm thick SiO2 gate dielectric layers. It was observed that the TFTs electrical output was improved after a soft thermal-treatment. A positive effect of structural modifications induced by such type of post-fabrication processing is thus suggested.  No changes of IGZO crystalline status could be detected by X-ray diffraction, the films remaining amorphous at the sensitivity limit of the apparatus.The influence of the thermal-treatment on structural features such as interface roughness or density, were inferred by X-ray reflectivity measurements. These results are discussed with respect to the TFTs performance trends.  Acknowledgments:This research was supported by the UEFISCDI PN-II-RU-TE-2014-4-1122.